A (transaction) searching technique of a database system is available. In the searching technique, a searching operation is performed in response to a plurality of search requests in the database system. Data are successively read from a database, and the searching operation is performed on each of successively read data in response to the plurality of search requests.
An exclusive control method of database is executed by performing a search operation and an update operation in a mixed fashion. The search operation is performed by referencing data only. The update operation is performed by generating a new version to data. In a technique contemplated in the exclusive control method, a version management table is arranged to manage multiple versions of data.
One system contemplated includes a database server serving as a front end responsive to a query to a database, and a plurality of database manipulation servers manipulating the database. The front end database server is connected to the database operation server via a network. The front end database server analyzes a query to the database including a plurality of database manipulation sentences including a structured query language (SQL) sentence. The database manipulation server determines at least one database manipulation sentence that is executed in response to one start request, and then partitions the sentences into groups. The database manipulation sentences in groups are then transferred to the database manipulation server at a time. The plurality of transferred database manipulation sentences are then started in response to a single start request.
If a transaction search is performed, a new search request may arrive at the database with the transaction search being in progress. The execution of the new search request is forced to wait until the end of the transaction search process. In this case, the waiting time for the new search request may be extended to time the transaction search process takes if the time is the longest. For example, if a new search request arrives at the database immediately subsequent to the start of the transaction search process, a response of an operation to the new search request may take about twice the time of the transaction search process. If a new search request arrives at the database immediately prior to the end of the transaction search process, a response of an operation to the new search request may take about the time of the transaction search process. The response of the operation depends on the timing of the arrival of the search request, and varies within a range of twice the time of the transaction search process. The same is true of an update request.